Well Water

In the United States, about 15% of the population relies on private wells to supply their water for everyday use. These wells are not regulated by the EPA as municipal water systems are, and the owners are responsible for ensuring their own water quality. In 1999 and 2000, private well contamination resulted in 26% of the reported cases of illnesses from drinking impure water, and it is suspected that many more cases were dismissed as stomach flu.

Types of Water Wells

There are primarily three types of private water wells:

  1. Dug wells are usually excavated by shovel or backhoes. They generally are 10-30 feet deep and lined (cased) with brick, tiles, or stone to prevent collapse and capped with stone or concrete to keep out contaminants. Because they are so shallow, these types of wells run the greatest risk of contamination.

  2. Driven wells draw water from just above the bedrock and are usually 30-50 feet deep. Pipes are driven through the sand and soil with a screen on the end to mechanically filter out sediments. A pump is located in the house or on the wellhead to provide constant pressure. Even though they run deeper, driven wells are at a moderate to high risk for contamination.

  3. Drilled wells are the deepest and extend 100-400 feet into the bedrock. Metal or plastic piping is used for the casing, and the water is usually pumped by a submersible pump located near the bottom of the well. Because they run so deep, they are the least likely to become contaminated with surface water, but are vulnerable if the well cap is cracked by age and extreme temperatures.

Water Well Problems

Owners of private wells tend to be lax about regular maintenance until a problem occurs and then face steep repair bills. It is recommended that you have the mechanical parts of your well tested every spring, test the water for pathogens once a year, and test for chemical contaminants at least once every two to three years. The most common private well problems are:


Well water across the U.S. is increasingly subject to contamination from the chemicals that are sprayed on fields, livestock waste, naturally occurring minerals in the soil, and seepage from underground storage tanks. Increasingly, the people that rely on private wells for their water are installing water filters in their homes to filter out these contaminants and reduce the risk of waterborne illnesses. These filters range from whole house systems that employ several methods of filtration to simple pitcher water filters that are only used for drinking water.

If you�re interested in getting your well water tested, contact your county health department for a list of state-certified laboratories that will screen your water for contaminants and give you a report.